1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright (c) 2021, Oracle and/or its affiliates. */ 3 4 #include <test_progs.h> 5 6 /* Test that verifies exception handling is working. fork() 7 * triggers task_newtask tracepoint; that new task will have a 8 * NULL pointer task_works, and the associated task->task_works->func 9 * should not be NULL if task_works itself is non-NULL. 10 * 11 * So to verify exception handling we want to see a NULL task_works 12 * and task_works->func; if we see this we can conclude that the 13 * exception handler ran when we attempted to dereference task->task_works 14 * and zeroed the destination register. 15 */ 16 #include "exhandler_kern.skel.h" 17 18 void test_exhandler(void) 19 { 20 int err = 0, duration = 0, status; 21 struct exhandler_kern *skel; 22 pid_t cpid; 23 24 skel = exhandler_kern__open_and_load(); 25 if (CHECK(!skel, "skel_load", "skeleton failed: %d\n", err)) 26 goto cleanup; 27 28 skel->bss->test_pid = getpid(); 29 30 err = exhandler_kern__attach(skel); 31 if (!ASSERT_OK(err, "attach")) 32 goto cleanup; 33 cpid = fork(); 34 if (!ASSERT_GT(cpid, -1, "fork failed")) 35 goto cleanup; 36 if (cpid == 0) 37 _exit(0); 38 waitpid(cpid, &status, 0); 39 40 ASSERT_NEQ(skel->bss->exception_triggered, 0, "verify exceptions occurred"); 41 cleanup: 42 exhandler_kern__destroy(skel); 43 } 44